Gun sighting telescope

ABSTRACT

The invention relates to a gun sighting telescope with adjustable magnification and is characterized by an arrangement (10, 11) by which elevation adjustment of the sighting telescope is automatically controlled when the magnification factor of the sighting telescope is changed, preferably such that the elevation adjustment automatically compensates for a bullet drop along a known trajectory when the magnification factor is controlled such that the image of a target viewed from said sighting telescope at different ranges therefrom appears to be unchanged in size.

This application is entitled to benefit of the filing date ofInternational Application No. PCT/SE86/00218 filed May 9, 1986 under thePatent Cooperation Treaty.

BACKGROUND OF THE INVENTION

The present invention relates to a gun sighting telescope.

SUMMARY OF THE INVENTION

It is the object of the invention to provide a gun sighting telescope ofthe type referred to, in which a change of the magnification factor isautomatically accompanied by a change of the elevation adjustment of thesighting telescope.

A further object of the invention is to provide a gun sighting telescopein which a point on the reticle or like sighting mark of the telescopecovers an unvaryingly large area of a specific target, irrespective ofthe distance to the target, if the target is magnified in the sightingtelescope by adjustment of the magnification factor to an image sizewhich, to the eye, appears to be essentially the same. A specific objectof the invention is to provide an arrangement which, in a gun sightinginstrument of the type here concerned, automatically changes theelevation adjustment of the telescope with due regard to the distance tothe target to compensate for the drop of a bullet following a specific,known trajectory.

These objects have now been achieved by imparting to the gun sightingtelescope according to the invention the characteristic features statedin the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described in more detail below, reference beinghad to the accompanying drawing which is a schematic and fragmentaryaxial section of a gun sighting telescope designed in accordance withthe invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The main components of the gun sighting telescope illustrated, such asthe telescope barrel, i.e. the outer tube 1 with the objective lens 2,the ocular lens 3 and a reticle 4 in the object plane of the ocularlens, two relatively and axially adjustable holders, in this instancetwo telescopically displaceable inner tubes 5, with the associated innerlens system 6 and the adjusting device 7 for changing the magnificationfactor, are of per se known design and arranged in conventional manner.

A cam follower means 10 is mounted in the outer tube 1, and one of theinner tubes 5 is connected with a cam means 11, the cam surface 11' ofwhich is engaged by the cam follower means 10. The cam means 11preferably is resilient or spring-biased such that the two means 10, 11will always be in contact with one another.

In the embodiment illustrated, the cam follower means 10 preferably isthe elevation adjustment screw of the telescope, although the screw hereacts upon the inner tube 5 via the cam means 11. Upon displacement ofthe two inner tubes 5, 5' by means of the adjusting device 7 forchanging the distance between the lenses of the inner lens system, andthus the magnification factor, the cam means 11 is moved in anessentially straight axial path together with the corresponding innertube 5 and thus in relation to the cam follower 10, the angle ofelevation adjustment of the two inner tubes 5 within the outer tube 1being changed in dependence upon the cam surface profile.

As already mentioned, the reticle 4 in the embodiment illustrated liesin the object plane of the ocular lens 3, and the image is not magnifiedby the reticle, at least not to any appreciable degree, if themagnification factor of the sighting telescope is increased.

This is important because in this manner a point, for example thecrossing point, on the reticle will always cover an unvaryingly largearea of a target which is located at varying distances from the sightingtelescope but which, if the magnification factor of the telescope ischanged, causes the marksman to see in the telescope an image which hasnot changed its size.

This in turn means that, if the marksman is aiming at a target, forexample the head of a hare, and if the marksman by reticle selection hasfound that the above-mentioned point exactly covers the hare's head at atarget distance of, for example 100 meters at a certain magnificationfactor, the point will cover the hare's head also at a distance of, forexample, 500 meters, if the magnification factor is increased, so thatthe hare's head in both cases appears to the marksman's eye to be ofunvarying size. Moreover, this means that, if the magnification factorof the sighting telescope is adjusted such that the point in questioncovers the head of a hare, the magnification of the sighting telescopehas been essentially correctly adjusted, irrespective of the distance tothe hare, or any hare, because the heads of different hares are not muchdifferent in size, at least from a practical point of view.

However, different ranges require compensation of the elevation of thesighting telescope in dependence on the trajectory. Bullets fromcartridges of a given cartridge type (charge, weight of bullet, etc.)follow essentially the same trajectory when fired from a given type ofbullet-firing firearm. The marksman who has knowledge of the trajectoryselects such a cam profile for the cam means 11 that adjustment of themagnification factor of the sighting telescope is automaticallyaccompanied by a correction of the elevation adjustment to compensatefor the bullet drop along the trajectory. In the assumed case, thehare's head will therefore be hit by a sure marksman irrespective of therange within reasonable limits, say from 50 to 600 meters, provided thatthe above-mentioned point covers the hare's head, neither more nor less.

If the relative adjustment of the movable and the stationary componentsof the gun sighting telescope is graduated in meters instead of in themagnification factor, the marksman, if he so desires, obtainsinformation of the range.

If the trajectory is a different one, it is of course necessary to use adifferent cam. It is possible to use a rotatable disk (not shown) or thelike with different cams 11' for a limited number of differenttrajectories. If the cam means is mounted inside the outer tube 1, andif the cam follower is mounted on the outer side of the inner tube, sucha disk etc. with different cams can be easily rotated or displaced bymeans of an adjusting member accessible on the outer side of the tube 1.

Instead of adjusting the sighting telescope such that a part of therecticle or like sighting mark covers an area corresponding to the headof a hare, it is of course possible to use a dot, a circle or anysighting mark whatsoever for covering areas which are fairly equal insize on any target whatsoever, for example the bull's-eye of a target orthe head of a cardboard silhouette during field firing at differentranges, for which last-mentioned use the gun sighting telescopeaccording to the invention is especially serviceable.

Naturally, the invention is not limited to gun sighting telescopes ofthe type illustrated in the drawing, but may be used with any sightingtelescopes whatsoever, within the scope of the appended claims.Furthermore, the cam means and the cam follower may be designeddifferently and mounted in different positions than in the drawing, andof course also within the scope of the appended claims. In particular,it should be noted that the important feature is that either one of thecam follower/cam means is displaced together with one of two lensarrangements relatively and axially adjustable for varying themagnification factor and, in collaboration with the other of said camfollower/cam means, controls the angle between the optical axis of theinner lens system, i.e. the common center line of the inner lensarrangements 6', 6", in relation to the common center line of theobjective lens and the occular lens, such that the elevation adjustmentof the sighting telescope is changed in dependence on the change of themagnification factor, in the manner described.

I claim:
 1. A gun sighting telescoping a recticle (4) in the objectplane of the ocular lens (3), a frame, a device (7) mounted on saidframe for adjusting the axial distance between two lens arrangements(6', 6") included in an inner lens system (6) between the ocular lens(3) and the objective lens (2) for changing the magnification factor ofthe sighting telescope, and at least one device for adjusting the angleof elevation of the sighting telescope in dependence on the adjustmentof the magnification factor of the sighting telescope, said elevationangle adjusting device comprising a device consisting of a cam means(11) and a cam follower means (10), one of which is fixed relative toeither one of the lens arrangements (6', 6") of the inner lens system,the outer means being fixed relative to said frame (outer tube 1) of thesighting telescope, said cam means and said cam follower means (10, 11)are so arranged that, upon a change of the magnification factor, achange of the distance between the lens arrangements (6', 6") of theinner lens system (6) automatically changes the elevation angleadjustment of the inner lens system and thus the angle between theircommon center line, i.e. the optical axis, and the corresponding axis ofthe objective lens (2) and the ocular lens (3) and said ocular lens (3)and said reticle (4) are so arranged relative to the rest of the lenssystem that upon a change of the magnification factor of the sightingtelescope, the image of the reticle has essentially the same size suchthat a point on the reticle covers substantially the same area on anobject whose image in the sighting telescope has been adapted,irrespective of the distance to said object, to a specific size ofadjustment of the magnification factor.
 2. A gun sighting telescope asclaimed in claim 1 in which said cam means (11) has a profile so adaptedto a given known trajectory that changing the elevation of the sightingtelescope upon adjustment of the magnification factor for differentranges within at least a selected range area is automaticallycompensated for with regard to the bullet drop along the trajectory. 3.A gun sighting telescope as claimed in claims 1 or 2, in which said camfollower means (10) is a per se known elevation adjustment screw of thetype usually provided on conventional sighting telescopes, said screwalso providing means to actuate the inner tube (5) via the cam means(11).
 4. A gun sighting telescope as claimed in claim 2 in which thereare provided several cam means of one cam means having several camprofiles (11'), and that said cam means or cam profiles are designed tocompensate for elevation adjustment of the sighting telescope, each forone trajectory, and are selectively adjustable for cooperation with thecam follower means (10).